package com.leetcode.t27;

/**
 * 给定一个二叉树，判断它是否是 平衡二叉树
 * 示例 1：
 *
 *
 * 输入：root = [3,9,20,null,null,15,7]
 * 输出：true
 * 示例 2：
 *
 *
 * 输入：root = [1,2,2,3,3,null,null,4,4]
 * 输出：false
 * 示例 3：
 *
 * 输入：root = []
 * 输出：true
 *
 *
 * 提示：
 *
 * 树中的节点数在范围 [0, 5000] 内
 * -104 <= Node.val <= 104
 */
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public boolean isBalanced(TreeNode root) {

    }
}